Tribological Properties of Gold for Electric Contacts

The basic mechanisms of wear and lubrication of gold-based contact materials, particularly eiectrodeposits, from the point of view of separable connectors and instrument slip rings, are reviewed. Specific recommendations are made for optimizing contact finishes for practical devices. Included are a discussion of the following. 1) The categories of metal transfer and wear (such as prow formation) and of transition phenomena that control the sliding mechanism. 2) Theories that have been advanced to explain sliding behavior based On bulk and on surface properties of the contact material. 3) The dependence of contact lubrication on physical properties of the lubricant and topography of the contact. 4) The potential role of underplate in improving a gold contact materials system, including reduction in wear and friction, minimization of susceptibility to corrosion in polluted atmospheres, and elimination of degradation due to thermal diffusion of elements from the substrate through the gold.